115628
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Mapa Mental por harry_bygraves, actualizado hace más de 1 año
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Creado por harry_bygraves
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Pest control
- A pest is any organism that has as undersierable effect. In farming it
may cause harm economically, or effect the health of crops of livestock
- Pests can have a devastating effect on crops, especially in
monocultures in which only crop is grown. Monoculture systems are
simpler than natural ecoosystems and usually lack pest predators
- Pests can equally have a damaging effect on livestock reared in crowded
conditions. In crowed conditions, the high reproductive output of the
parasite can lead to its rapid transmission from one host to another
- Most pests cause significant economic harm only when their population
reaches a certain level, called the economic injury level. To prevent
fast-growing pest populations from reaching this level, control measures
have to be started at a lower pest population level, called the economic
damage threshold. Pests may be controlled chemically, biologically, by
cultural methods, or by a combination of methods
- Cultural methods of pest control; such as weeding, tillage, and
crop rotation are amoung the most common. Crop rotaion often
prevents the build up of pests that occur in monocultures, but it
is only effective when a pest cannot attck successive crops.
- Crop damage can also be minimised by growing the crop at a particular time in the life cycle of a pest. The crop is sowed or harvested
at times when the pests can do least damage. Other cultural methods of pest control include; creating physical barriers; intercropping
- Chemical control; toxic chemicals that control pest populations are called pesticides. These
include; fungicides, herbicides, and insecticides. Contact pesticides kill pests without being eaten,
systemic pesticides are taken into a plant and translocated within the plant, and enter the pest
when it eats the plant or sap. Broad-spectrum pesticides, designed to affect a wide range of
pests, may also kill harmless organisms or beneficial ones such as the predators of pests
- Biological control; is the control of pests
and weeds by other living organisms or by
bioloigical agents. A predator or parasite
is usually used to control the pest. The
aim is not to eliminate the pest or weed,
but to use the control organism to keep
the pest or weed population below the
economic injury level. Care must be taken
to ensure that the control organism does
not become a pest itslef.
- Biological agents inlcude pheremones genetically engineered insecticides.
Pheremones are chemicals released by the organism. Synthetic
pheremones have been used to lure pests onto traps laces with insecticides
- Biological agents inlcude pheremones genetically engineered insecticides.
Pheremones are chemicals released by the organism. Synthetic
pheremones have been used to lure pests onto traps laces with insecticides
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